A new study from a nonpartisan think tank says immigrants played a founding role in more than half of the 87 American startups with billion-dollar-plus valuations.

The report, by the National Foundation for American Policy, says at least 51 percent of these so-called unicorn startups, valued at a billion dollars or more, had at least one immigrant founder. Put those 44 companies together, and they’re worth a collective $168 billion. The study cites companies like Stripe, ZocDoc, Cloudera, FanDuel, and Mu Sigma among the startups with immigrants serving in roles like CEO, CTO, or vice president of engineering.

India topped the new list, with 14 of the billion-dollar startup founders hailing from the country, and Canada and the U.K. tied for second place, with eight each.

The foreign-born entrepreneurs also create an average of 760 U.S.-based jobs per company, the study says.

The report comes as tech entrepreneurs like Mark Zuckerberg rally to make it easier for workers to secure more H-1B visas they say are a boon for the tech industry. These are the temporary stay passes that permit highly skilled employees to work in the country. But some say these kinds of short stays simply promote cheap labor practices.

The application window for these visas, which opens in April, is greeted with an onslaught of applications every year, which top the 85,000 visa slots within days. This month the White House announced a new push to extend certain visa stays for foreign students, but only those graduating from STEM (science, technology, engineering and mathematics) programs.